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Water Management 101 Table of Contents WATER MANAGEMENT 101 TABLE OF CONTENTS BETTER SUBSURFACE WATER MANAGEMENT DRIVES YIELD AND LOWERS RISK .............................................................3 WATER MANAGEMENT 101 .......................................................................................................................................................3 3 Goals of a Drainage System ...............................................................................................................................................4 Tile Spacing and Depth ..........................................................................................................................................................4 Drainage Coefficient ..............................................................................................................................................................5 THREE DRAINAGE MYTHS WE BET YOU’VE HEARD BEFORE .................................................................................................5 Tiling the wettest field = best ROI .........................................................................................................................................5 My crop will be hurt by drain tile in a dry summer. ..............................................................................................................5 Tile is really expensive. ..........................................................................................................................................................5 THE PROOF IS IN THE YIELD .....................................................................................................................................................5 Yield Improvements from Drainage ......................................................................................................................................6 Controlled Drainage/ Water Management Systems.............................................................................................................6 Subirrigation ..........................................................................................................................................................................7 INCLEMENT WEATHER EVENTS ...............................................................................................................................................7 DIGGING DEEPER INTO DRAINAGE ..........................................................................................................................................9 Salinity ....................................................................................................................................................................................9 Impacts and Ideas On Salinity ...............................................................................................................................................9 Water Quality and Environmental Benefits .........................................................................................................................10 Sodicity .................................................................................................................................................................................10 Tile Spacing & Patterns .......................................................................................................................................................10 AN INVESTMENT MENTALITY ..................................................................................................................................................10 Soil Productivity ...................................................................................................................................................................10 Weather History ...................................................................................................................................................................11 Drainage Coefficient ............................................................................................................................................................11 Crop Value and Potential .....................................................................................................................................................11 ©2019 ELLINGSON COMPANIES. ALL RIGHTS RESERVED. ELLINGSONCOMPANIES.COM 2 BETTER SUBSURFACE WATER MANAGEMENT DRIVES YIELD AND LOWERS RISK Many agronomists will tell you that next to proper pH, proper subsurface water management of the soil profile is the most important factor in maximizing yield potential. As part of a leading subsurface water management and trenchless construction company providing nationwide services, Ellingson Technology and Engineering is actively engaged in the critical dialogue about advancing subsurface water management practices and technology and the impact of evolving environmental regulations. The resources here share our insights gleaned from working with thousands of growers and notable clients across a variety of other industries, as well as relevant research findings from leaders in the marketplace. WATER MANAGEMENT 101 The agricultural practice of tile drainage is a method to effectively remove excess water from below the soil surface. For optimal crop growth, soil moisture levels must be kept in check. Too much water beneath the soil can be detrimental to the success of a healthy plant. Studies have shown that by correctly managing water on a field through drainage, one can see tremendous affect on a crop’s quality, consistency, and yield. A tile drainage system consists of a network of below ground pipes called laterals and mains that work together to manage the water table. The laterals are spaced throughout the field and collect water that travels to a main. The main allows the system to carry the water out of the field in a controlled and responsible fashion. An entire drainage system is designed on a grade (or slope) so the water flows in a specific direction. ©2019 ELLINGSON COMPANIES. ALL RIGHTS RESERVED. ELLINGSONCOMPANIES.COM 3 3 Goals of a Drainage System 1. Lower the water table. A good tile drainage system lowers the water table to a level that allows for (and encourages) strong root growth. The removal of excess water above the tile system, allows roots more room to grow and develop, which leads to healthier plants. 2. Remove water at the appropriate rate. A good tile drainage system can remove excess water from the root zone within the critical timeframe before harm is caused to the plant. If a crop is left saturated for too long, the plant will be dam- aged – adversely affecting yield. 3. Engineered for the field. A good tile drainage system is properly engineered for the specific field it serves – taking into account factors like soil properties, crop rotation and weather patterns. A modern tile system is designed with longev- ity in mind so that the investment is truly long-term. In an undrained field, poor drainage can cause shallow root growth and sometimes crop failure due to the plant not getting the oxygen it requires in the root zone. With tile drainage systems the roots have the room and oxygen to grow deeper into the soil, promoting stronger and healthier plants which can turn into higher yielding crops. The use of controlled drainage can help reduce nutrient loss (nitrogen and phosphorus) by holding the water in the soil profile for an extended amount of time – reducing the nutrient concentration of the water being discharged. Tile Spacing and Depth The spacing between tile and how deep it is laid in the ground will directly impact the subsurface water table. Between two tiles you will notice that the water table takes on a curved bell shape; this is because directly above the tile, the tile is able to pull the saturated level down to the level at which it is. As you move further away from the tile, the tile’s affect lessens on the water table line above it. With this principle at work, the water table’s highest point lies directly between two installed tile lines. Properly installed tile keeps the water table at an appropriate distance below the surface at all locations – which becomes a balancing act between spacing and depth. Soil type is a particularly important variable. As you’d probably imagine, porous sandy soils give ground water the ability to move more freely allowing for deeper and more widely placed tiles, whereas thicker clay soils demand closer shallower tile lines. Working with an engineer who understands all factors is critical to optimizing a drainage system’s design and performance. ©2019 ELLINGSON COMPANIES. ALL RIGHTS RESERVED. ELLINGSONCOMPANIES.COM 4 Drainage Coefficient Each drainage system is designed to a certain capacity. The design capacity of a drainage system is expressed as a depth of water removed in 24 hours (inches/day). For example, a ½ inch drainage coefficient means the system can remove ½ of an inch of water in a day. A drainage coefficient should be chosen that maximizes return on investment. This is ac- complished by determining the most economical means to minimize risks for your crop rotation. THREE DRAINAGE MYTHS WE BET YOU’VE HEARD BEFORE It’s understandable that a practice that’s been around so long has picked up some confusion and inaccuracies along the way. The very name “tiling” finds no modern connection, originating from the old material (ceramic tiles from fired clay) used in the practice historically. It’s no wonder certain myths are
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